Maintenance of a well for water: rules for the competent operation of a mine
To build a water intake well on the site is not the last task of the owner who decided to conduct autonomous water supply on the site. In order to be able to use the facility for more than a dozen years, it is necessary to regularly conduct maintenance of the well for water. For optimal results, you need to know how it is produced. Do you agree?
We will tell you what points to consider when operating a hydraulic structure. The article submitted for consideration describes in detail how to carry out these activities on their own. Based on our recommendations, your water source will work for a long time and flawlessly.
The content of the article:
- Rules for putting a well into operation
- Maintenance of the water intake
- Bleeding and maintenance flushing
- Frequent breakdowns and solutions
- Conclusions and useful video on the topic
Rules for putting a well into operation
A constructed water intake system having a circular cross section of small diameter needs preparation before putting it into operation. Upon completion of the installation, a trial run of the water-lifting equipment is carried out. Subsequently, the necessary repair of the structure is carried out.
Repair operations are based on the data of the passport attached to the drilled well.
It is recommended that the well be put into operation immediately after completion of the flushing procedure and trial pumping. If this event has to be postponed for any reason, then the wellhead is temporarily closed with a metal cover pre-welded to the casing. Such measures protect the entry of foreign objects into the structure.
Static Level Definition
When equipping a hydraulic structure, it is important to know its static and dynamic level. Both indicators are determined by simple measurements of a water mirror by a hydrogeological cracker or a regular polymer pipe replacing it.
When the annular edge of the pipe or cracker comes in contact with the water surface, a peculiar cotton is heard.
To determine the static level, you should not pump out the water from the development about a day before the measurement. The static indicator should give us the distance between the day surface and the underground water mirror at rest.
The dynamic level is determined vice versa after pumping. This indicator is also necessary to determine the exact installation depth. submersible pump. In addition, the difference between static and dynamic values will determine the flow rate of a personal water source. It is necessary for the selection of pumping equipment.
The pump is positioned 3-5 meters below the dynamic level mark. During the operation of the equipment it is important to control what is the height of the water column below it.
For example, when using vibrating submersible pumps, it is recommended that between the bottom of the output and the bottom of the device should be at least 1 - 1.5 m. A number of centrifugal pump systems can be positioned at a distance of 0.5 m from the bottom.
The permissible installation depth of the pumps is indicated by the manufacturers. Their recommendations should be carefully studied and followed. In the case of an unstable and slowly recovering level in a water well, it is recommended to purchase pumps with sensors that fix the mirror lowering below the permissible limit.
The automatic device will automatically stop the pump if the water column is not enough for normal pumping of water.
If the operated well for water has a low static level, test pumping is performed with a small pump capacity. And the subsequent operation begins with a minimum flow rate, increasing it over and over until it reaches the design capacity specified in the passport.
The first water withdrawal procedure should last at least one and a half to two hours. To determine the amount of water supplied from the well, use a ten-liter bucket.
When filling the tank, you need to use a stopwatch to record the time. To determine the flow rate, only the resulting volume of 10 liters remains divided by the time spent.
Normal is considered performance:
- for sand wells - 1.5 cubic meters per hour;
- for artesian - 3 cube / hour.
Comparing the obtained indicator with the norm, if necessary, adjust the pump. In case of large differences in measurements, before proceeding with the installation of the pump, it is still worth consulting with specialists of the relevant organizations.
Preparation of pumping equipment
The first step is to check the internal diameter of the installed casing pipes. This parameter should be 2-4 cm larger than that of the installed unit. Measurement work is carried out to a depth of 10 meters within the mark where the pumping equipment is supposed to be located.
Only pumping devices of those design types that are recommended in the passport attached to it should be installed in the well. Installation of equipment must also be carried out in strict accordance with the passport and the operating instructions attached to it.
At the first start-up of the pump, the installed equipment should be switched on as smoothly as possible, first with a productivity of 40-50% of the design capacity, and gradually increasing to the recommended water withdrawal value.
In the next few starts, at the initial stage of operation, the pump should also be started up-stream. At the same time, it is advisable to avoid short and frequent shutdown of the unit.
If a water level fluctuation is detected during pumping, or if it is intermittently supplied, the pump must be turned off for a while. This phenomenon may occur if the device is not assembled correctly. The problem can only be solved by repair work.
The equipment should also be turned off if clay and sand impurities are found in the pumped water. But before that, it is necessary to reduce the flow of water through a valve installed on the discharge pipe. Otherwise, small parts, falling into the pump casing, will settle in its flowing part, causing the mechanism to fail.
Chemical water analysis
Upon completion of the selection, it is advisable to conduct chemical analysis of water. This will determine whether it meets the standards, and if necessary, select the best option for a water treatment system.
Chemical analysis of water is recommended not earlier than three weeks after the launch of the hydraulic structure. At this point, the static position of the water level is stabilizing, and the overall picture will become clearer.
Maintenance of the water intake
To ensure long and trouble-free operation of the hydraulic structure, it is important to provide qualified service. Ideally, it is better to entrust this work to an experienced specialist who has studied geological documentation and knows all the nuances and subtleties of well operation.
But in the absence of the opportunity to use the services of a master, the operation of a water well can be carried out on its own.
Monitoring the operation of the structure includes a number of basic types of work.
Well productivity measurements
Regular measurements of well productivity should be performed during operation. They are carried out using the same technology that was used during the first launch of the hydraulic structure.
If two measurements made with a certain time interval show different filling rates, this indicates the instability of the flow rate. So, pumping equipment should be selected according to the highest value.
Note that exceeding the operating parameters entails premature failure of the pump unit.
An excessively powerful pump in workings with a small flow rate can cause water shortages and will not create sufficient pressure. However, its productivity should be sufficient to provide water to all water intake points available at the facility.
Checking pump performance
Pumping equipment, even if operating properly, must be checked at least once every six months.
The check is performed in the following sequence:
- Visually inspect equipment to determine the integrity of the housing and the tightness of all types of connections.
- Turn off the unitthen open the water intake valve and measure the pressure in the system. This parameter should drop to the “0” mark.
- Check the pressure in the hydraulic tank. This is done using an automobile pressure gauge, which is connected to the tank nipple. The difference in values when the pump is on and after it is turned off must not exceed 10%. If necessary, air is pumped through the same nipple using a conventional compressor.
- Turn on the pump and monitor its work. When the pressure parameter set by you on the device relay is reached, the pump should shut off.
- Recheck system pressurebut already in the absence of consumption. If the equipment operates correctly, the relay indicator should be on the red arrow, which corresponds to the maximum pressure mark.
- To check the correct operation of the pump for a while open the water tap. When the pressure in the system drops, the pump should turn on automatically. Then the valve is closed, the pressure level is checked again and the unit is turned off.
The frequency of preventive examination of pumping equipment is usually indicated in the passport to the product.
The results and marks on preventive examinations of the well should be recorded in a special journal, indicating the date and name of the employee who carried out the control. These indications will help diagnose possible malfunctions of both pumping equipment and the well as a whole.
Preventive repair of pumping equipment with the replacement of worn parts should be done at least once every six months. For equipment operated irregularly, the interval between preventive measures can be increased to 9 months.
Water properties control
The physical properties of water should be monitored daily:
- smell - normal natural water should not smell.
- Colour - the color change depends on the substances that are dissolved in it, for example, iron colors it in a yellowish tint, and clay in red-brown;
- turbidity - this indicator is manifested with an increased concentration of contaminants in the water;
- taste - deterioration in taste indicates the presence in the water of a high concentration of manganese, magnesium or iron.
Conducting a standard comprehensive analysis for microbiological and chemical studies can be ordered at government agencies or private laboratories.
To obtain the most accurate result, it is important to use only a clean sterile container made of plastic or glass with a capacity of up to 2 liters. Bottles must be filled so that no air bubbles form.
Selected water must be delivered to the laboratory within 72 hours. Water samples delivered later lose their properties and therefore do not give a clear picture.
Bleeding and maintenance flushing
The drilled well is necessarily pumped, cleaning it from the sediment that has crumbled during drilling.
The work can be performed using:
- special installation for washing;
- compressor with a capacity of 12 atmospheres;
- submersible pump.
Any of these methods is based on the fact that air or water under pressure will push dirty water along with inclusions to the surface.
Procedure for rocking well:
- With the help of a strong cable, a pump is immersed at the bottom of the well, which will pump out the liquid.
- A hose is attached to the outlet nozzle of the unit and it is taken away from the well in order to prevent re-contamination of the structure.
- Start the unit and pump out the liquid until it becomes transparent. The process can take several hours. During this period, a layer of coarse-grained sand or fine gravel may accumulate in the region of the filtering section of the casing, which will subsequently act as a filter.
Some firms involved in drilling wells recommend that, during the operation of structures, they are flushed from time to time and sand cleaning. The main argument is to prevent siltation of the lower part of the trunk.
Preventive flushing only makes sense if the well is used seasonally and at long break intervals. For permanently working structures, such flushing is not necessary. After all, a well is washed daily with a pump.
Additional flushing may be required only if there is a malfunction in the work, or if the pumping equipment does not cope with the task.
Frequent breakdowns and solutions
During the operation of a hydraulic structure, there is always the possibility of breakdowns. Some of them can be eliminated on their own, without resorting to the services of expensive specialists.
Sand entering the water at the bottom of the well
This can occur due to a violation of the tightness of the casing, or if the head of the well is periodically flooded with wastewater. Confirmation of this will be the appearance of new impurities and turbidity in the water.
Clearing the barrel with a cylindrical chipper helps to solve the problem.
Having scooped up silt and sand drill bit, the well is pumped until clean water appears. In the future, in order to prevent a recurrence of the situation, from the outside of the walls of the casing string, the voids are filled with waterproof clay, covered with a layer of gravel or filled with cement mortar.
The reason for this is all the same small particles of sand or gravel, which clogs the holes. Usually this problem occurs a couple of years after the launch of a sand well.
In case of integrity violation downhole filter or a critical drop in bandwidth solves the problem by replacing.
But this method is used quite rarely, only as a last resort, since it is not always possible to dismantle the casing without collapsing the walls of the structure.
It often happens that due to improper installation, the cable fixing pumps and hoses break under the influence of load and vibration during equipment operation. Or a stone or a bolt that accidentally falls into the well and falls into the gap between the pump unit and the wall, wedges the equipment and provokes the device from becoming stuck.
You can remove the pump and fasteners using hooks or cat-type fixtures. The extraction operation should be carried out with extreme caution.
If during the lifting process the devices break off and remain in the barrel of the column, the task of removing the device will become more complicated several times.
If the unit is stuck tightly, the most correct decision is to call a team of specialists. Using an underwater video camera and other equipment, they can diagnose the problem and fix it without damaging the structure.
Most often with jamming of the pumping device in the second or third from the top link of the casing string, it is partially removed from the mine. Then the pipes are disconnected to the place of clogging from the trunk and the pump is taken out. If necessary, the damaged links are replaced with new pipes of the same diameter.
Conclusions and useful video on the topic
Video # 1. How to equip a well after drilling:
Video # 2. Pumping out sand from a well:
Video # 3. How to determine the presence of heavy metals in water using improvised means:
Regular downhole maintenance is not a difficult task to fulfill, which any owner who has at least the slightest idea of the system’s operation can cope with.
It is not worth neglecting preventive measures, since restoration of a “neglected” well will cost several times more than minor regular repairs.
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